Along with the development of communication technologies, various network access technologies have been used in current networks. On the one hand, new network devices may be selected during the building of networks so as to provide a signal card with better services, and old network devices may continue to be used so as to reduce cost and provide users with services. On the other hand, operators may select different network technologies to provide different types of services. As a result, for the network devices of an identical operator, the network will be built by using different access technologies. This requires that a communication terminal can select a suitable network access technology in accordance with a current service type and a network resource status, so as to obtain better services.
In the prior art, it is impossible to implement video phone services on a single-card-dual-standby communication terminal. This is because the video phone services, as Circuit Switched (CS) domain services, cannot be supported by a GSM network. Although a TD-SCDMA network can be used to implement the video phone services, the single-card-dual-standby communication terminal will, by default, preferably register the CS domain services in the GSM network and register Packet Switched (PS) domain services in the TD-SCDMA network.
The inventor finds that there exists the following problem in the prior art, i.e., in the existing communication networks, the GSM network can support the CS domain services but cannot support the video phone services. As a result, it is impossible for the existing single-card-dual-standby communication terminal to implement the video phone services.